Node suspended flexible rocket

ABSTRACT

This invention relates to modifying a fairly conventional spin stabilized rocket by locating the bearings which support the spinning rocket at the nodes of the primary bending mode of the round. This structure allows higher spin rates than with current designs by reducing the sensitivity of the round to spin-induced bending.

Unlt'ed States Patent- 1191 3,857,320 Conard Dec. 31, 1974 [54] NODE SUSPENDED FLEXIBLE ROCKET 3,084,598 4/1963 Coslowsky... 89/ 1.808 inventor: Robe" G. Cunard, Huntsville Ala. 3,610,096 10/1971 Bauman et al 89/l.808

[73] Assignee: The United States of America as Primary Examiner samuel w gngle represented h) the Secretary of the Attorney, Agent, or Firm-Edward J. Kelly; Herbert Army, Washmgton, Berl; Herbert H. Murray [22] Filed: Jan. 29, 1973 Y I [21 Appl. No.: 327,517 ABSTRACT This invention relates to modifying a fairly conven- 52 us. (:1. 89/1.808, 89/l.816 tiohal P Stabilized rocket by locating the hearings 51 Int. Cl F4lf 3/04 which PP the Spinning "whet the nodes of the [58] Field of Search 89/l.808, 1.8, 1.816 Primary bending mode of the roundhi Structure lows higher spin rates than'with current designs by re- 5 References Cited ducing the sensitivity of the round to spin-induced UNITED STATES PATENTS bendmg' 2,968,996 l/l96l Strickland et a1 89/].808

.1 Claim, 3 Drawing Figures PATENTED BEB3 1 I974 FIG. 2

1 NODE SUSPENDED FLEXIBLE ROCKET BACKGROUND OF THE INVENTION In the previous use of high spin rates above, say, 7,000 or 8,000 rpm, the residual dynamic unbalance within the missile will cause the missile to bend within the launch tube. This bending causes the principal 1ongitud'inal axis of inertia to depart from the longitudinal axis of the launcher and causes the missile to kick sideways when it changes from the clamp-clamp mode within the launch tube to the free-free mode after the missile leaves the launcher. 7

It is therefore an object of this invention to provide means to prevent displacement of the longitudinal axis of inertia from the longitudinal axis of the launcher while the missile is in the launcher.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a conventional spin stabilized rocket constructed in accordance with the prior art.

FIG. 2 illustrates the rocket of the present invention.

FIG. 3 is a section taken on line 33 of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein FIG. 1 illustrates the prior construction and FIG. 2 illustrates the construction according to the present invention, indicates the launch tube. The missile 12 is mounted within the launch tube within a pair of bearings 14 and 16. The forward bearing 16 is provided with four outwardly extending fins 18, 20, 22 and 24 which ride in slots provided in rails 26, 28, 30 and 32 respectively formed within the launch tube in the manner illustrated in FIG. 3. Y

In the missile 12, illustrated in FIG. 1 as representing the prior art, the rear bearing 14 is mounted adjacent the rear end of the missile and the forward bearing 16 is mounted adjacent the mid point of the missile. When a missile mounted in this manner is spun above 7,000 or 8,000 revolutions per minute, the missile due to residual dynamic imbalance tends to bend in the manner illustrated by the dotted line 40 thus displacing the longitudinal axis of inertia of the missile at an angle to the longitudinal axis of the launcher. When this occurs, and the missile is launched, the missile will assume a flight path dictated by the longitudinal axis of inertia which will be different from the direction indicated by the attitude of the launch tube.

Referring now to the missile of the present invention as illustrated in FIG. 2, the bearings 14 and 16 are moved to the node points for the bending mode of the missile and the missile will bend to the position illustrated by the dotted line 42. Since the bearings 14 and 16 are mounted at the bending nodes, the longitudinal axis of inertia of the missile will not deviate from and will be coincident with the longitudinal axis of the launcher so that when the missile exits from the launcher it will continue on the flight path indicated by the attitude of the missile launcher.

From the foregoing description it may be appreciated that mounting of the bearings 14 and 16 at the node points of the missile much higher spin rates may be employed for the missile without causing deviations of the missile flight path from the desired flight path due to the bending of the missile caused by centrifugal forces at extremely high spin rates.

I claim:

1. In combination with alaunch tube having a rear smaller diameter portion and a forward larger diameter portion,

a spin stabilized missile semblies mounted thereon,

each of said bearing assemblies comprising an inner and an outer race and a seriesof balls therebetween, I

the inner race of the rearmost bearing assembly being mounted on said missile at therear bending node of the missile and the outer race bearing against the wall ofthe smaller diameter rear portion of said launcher,

a plurality of longitudinally extending slotted rails mounted in the forward larger diameter portion of said launcher,

the inner race of the forward bearing assembly being mounted on said missile at the forward bending node of said missile,

fins attached to the outer race of said forward bearing assembly and slideably received in the slots in said rails,

whereby the support being at the node points wherein there is no movement relative. to said launcher the missile principal longitudinal axis of inertia will remain coincident with the longitudinal axis of the launcher regardless of any bending of the missile induced-by rotation thereof.

having two ball bearing as- 

1. In combination with a launch tube having a rear smaller diameter portion and a forward larger diameter portion, a spin stabilized missile having two ball bearing assemblies mounted thereon, each of said bearing assemblies comprising an inner and an outer race and a series of balls therebetween, the inner race of the rearmost bearing assembly being mounted on said missile at the rear bending node of the missile and the outer race bearing against the wall of the smaller diameter rear portion of said launcher, a plurality of longitudinally extending slotted rails mounted in the forward larger diameter portion of said launcher, the inner race of the forward bearing assembly being mounted on said missile at the forward bending node of said missile, fins attached to the outer race of said forward bearing assembly and slideably received in the slots in said rails, whereby the support being at the node points wherein there is no movement relative to said launcher the missile principal longitudinal axis of inertia will remain coincident with the longitudinal axis of the launcher regardless of any bending of the missile induced by rotation thereof. 